Annals of emergency medicine
-
Since the implementation of a paramedic system in Seattle, yearly survival rates from out-of-hospital cardiac arrest due to ventricular fibrillation have averaged 25% without any significant increase over the years. Outcome for cardiac arrest associated with other rhythms has been poor: when asystole was the first rhythm recorded, only 1% of patients survived; when electromechanical dissociation was initially present, only 6% survived. ⋯ When outcome in 244 witnessed arrests was related to the times to beginning CPR and to initial defibrillation, mortality increased 3% each minute until CPR was begun and 4% a minute until the first shock was delivered. New strategies that minimize delays appear to have the greatest promise for improving survival after cardiac arrest.
-
An enzyme-linked immunoassay urine pregnancy test was used on a group of patients suspected of having an ectopic pregnancy. Patients were seen in the county hospital emergency department and had the urine test correlated with a serum beta-hCG level determined by radioimmunoassay. There were 884 patients with urine ICON-serum beta-hCG correlations. ⋯ Using a modified testing procedure, each of these produced a positive ICON. Of the 27 patients with an ectopic pregnancy the urine ICON was positive in 26. The urine ICON is an improved assay for hCG in patients suspected of having an ectopic pregnancy, and is ideally suited for ED use.
-
The use of nitrous oxide as an anesthetic or analgesic agent frequently raises concerns about the possibility of post-inhalational diffusion hypoxemia. We undertook a study in 20 healthy volunteers to determine whether hypoxemia occurs after the self-administration by face mask of a 50:50 mixture of nitrous oxide and oxygen for 15 minutes, followed by breathing room air. Blood gases were measured through an in-dwelling arterial cannula before, during, and after inhalation of the mixture, at time O, five, ten, and 15 minutes, and then 30 seconds, 45 seconds, 2 1/2 minutes, five, and ten minutes following room air breathing. ⋯ No subject demonstrated arterial hypoxemia at any time before, during, or after self-administration of the gas mixture. In the ten subjects who self-administered the control gas there were no significant differences in the PaO2 values while they breathed either gas at any corresponding sampling time. We conclude that diffusion hypoxia is not seen in normal subjects following self-administration of a mixture of 50:50 nitrous oxide and oxygen.